Concept Category 1: Display and Describe Data

DEFENSE PRACTICE Concept Category 1: Display and Describe Data

Review the following concepts in your CC1 packet: 1) Measures of Center: Mean, Median, and Mode 2) Box and Whisker Plots (features of, how to analyze) 3) Histograms (features of, how to analyze) 4) Dot Plots (features of, how to analyze) 5) Vocabulary related to shape of data (evenly distributed, skewed, symmetrical)

Sample Questions:

1. Imagine you are asking the following questions to 100 middle school students. For each, explain whether the question is:

● Statistical or Non-statistical

● Numerical or Categorical

Give a reason for each of your answers.

a. How old is your best friend?

b. What size shoe do you wear?

c. What is your favorite fruit?

2) In July 2015, the Los Angeles Dodgers scored the following number of runs.

4, 4, 9, 0, 2, 4, 1, 2, 11, 8, 2, 2, 5

What type of graph (dot plot, histogram, or box & whisker plot) would be best to display this data? Explain your reasoning. (You do not need to make the graph.)

3) Look at the dot plot shown below.

Hours Exercising Per Week

Number of Hours

a. How many people exercised more than 10 hours per week? ______b. What is the range of the data? ______c. Susan says that the maximum of the data shown on the dot plot is 8 hours because that is where most of the data is clustered on the graph. Do you agree or disagree with Susan? Explain your reasoning. d. Miles says that the data centers around 10 hours because 10 is exactly in the middle of 0 and 20 on the number line. Do you agree or disagree with Miles? Explain your reasoning. CC1 DEFENSE PRACTICE - ANSWERS

a.a. How old is your best friend?

- This is numerical because age is given in numbers.

- This is statistical because middle students will have best friends of different ages. We would not expect everyone to say the exact same age.

a.b. What size shoe do you wear?

- This is numerical because shoe size is given in numbers.

- This is statistical because middle students will have different size feet. We would not expect everyone to wear the same size shoe.

a.c. What is your favorite fruit?

- This is categorical because fruit is a category (not a number) and students will answer with a name of a fruit.

- This is statistical because middle students will have preferences. We would not expect everyone to like the same fruits.

2. A dot plot is the most appropriate graphical display to use with the Dodger’s data because there is a small amount of data to graph (only 13 data points) and the data has a relatively small range (11 runs).

3. a) 8 people exercised more than 10 hours per week. (Note: Do NOT include people who exercised 10 hours per week.)

b) The range is 16 hours. Range is the difference between the maximum data point and the minimum data point. The maximum is 20 hours and the minimum is 4 hours (2 is not the minimum because there is not a data point at 2.) 20 – 4 = 16.

c) Susan is incorrect. The maximum number of hours is 20. It is the largest number in the data. 8 hours is the most common result (the mode), but not the maximum number of hours. d) Miles is incorrect. He found the center of the number line (which is 10 hours). This is not always the same as the center of the data. There are 23 pieces of data. The center of the data is 8 hours because on the graph, 11 data points are on/below 8 hours and 11 data points are on/above 8 hours. That means that 8 hours is the center of the data.